1. Field of the Invention
The present invention relates to a method of preserving a recording head which uses a reactive ink, ink jet system including a set of recording head and ink tank as the form of preserving the recording head, and ink set including a recording ink and ink for preservation, applicable to the method of preservation.
2. Related Background Art
Japanese Patent 3,021,149 discloses a cartridge including a recording head and ink tank section from which the ink is supplied into the recording head, structured in such a way that the recording head and ink tank section can be removably attached to or detached from the cartridge, are connected to work in communication with each other while the cartridge is in service, and independently exchangeable after the recording is completed, to propose a method of improving preservability of the recording head while it is stored for extended periods, e.g., for delivery periods, removing limitations in delivery of the recording head, and improving freedom of handling by filling the recording head with a liquid for preservation (ink for preservation) which compositionally differs from the recording ink in that the colorant component is removed partly in a given quantity or totally from the recording ink before the initial use of the recording head.
However, a large quantity of the ink for preservation is needed, for the ink to completely replace a reactive ink by which the as-produced recording head is tested for the printed letters using an ink set including a reactive ink, then the recording head is filled with the ink for preservation making the complete replacement unpractical. The reactive component of the reactive ink, when not completely replaced and left in the recording head, may react with a component of the ink for preservation when the recording head is preserved for extended periods before or during the delivery, possibly deteriorating functions of the head.
The term xe2x80x9creactive inkxe2x80x9d used in this specification means the ink which includes a reactive component capable of reacting a colorant component of another ink, when it is mixed therewith, to form the precipitates. Some examples include color sets of a black ink and cyan, magenta or yellow color ink, wherein at least one of the color inks contains an additive (reactive component) which can degrade dispersion stability of the colorant in the black ink, when it is mixed therewith.
The present invention is developed to solve the above problems. It is an object of the present invention to provide a method of preserving a recording head which uses a reactive ink for recording to keep its designated functions without deteriorating them. It is another object of the invention to provide an ink jet system including a recording head in a suitable condition for preservation, and ink tank, removably attached thereto or detached therefrom, which are connected to each other when a reactive ink for recording is supplied into an ink flow path in the recording head for sustaining recording.
The first embodiment of the present invention relating to a method of preserving a recording head for ink jet which can attain the above object includes a liquid flow path by which the ink is supplied and a discharge port in communication with the ink flow path to discharge the ink supplied into the ink flow path; is connected to an ink tank in the recording apparatus in such a way to be removably attached to or detached from the ink tank, to allow the ink to be discharged from the discharge port; and uses a reactive ink as the recording ink containing a colorant and reactive component reactive with another ink, comprising
a step of examining discharging conditions of the recording head using an ink for examination of a composition free of the reactive component, which is supplied into the ink flow path, and
a step of preserving the recording head for preservation by replacing the ink for examination remaining in the ink flow path in the recording head by an ink for preservation containing neither the colorant nor reactive component, after the step of examining discharging conditions is over.
The recording head can be used for recording by, e.g., replacing the ink for preservation by the reactive ink for recording.
The recording head is preferably structured with a base comprising a board which supports a heat-generating resistor forming the heat-generating section, electrode wiring electrically connected to the heat-generating resistor and cavitation-resistant film provided on the heat-generating resistor and electrode wiring via an insulating/protective layer, wherein the ink flow path can be structured to correspond to the heat-generating section, and the cavitation-resistant film can have a Ta or TaAl film at least in the portion which comes into contact with the ink.
Moreover, the ink jet system of the present invention, kept in a suitable condition to be preserved, includes a recording head for ink jet and ink tank which can contain the ink, wherein
the ink tank has a section which holds the reactive ink for recording, containing a colorant and reactive component reactive with another ink,
the recording head includes a liquid flow path removably attached to or detached from the ink tank and supplied with the ink when attached to the tank, and a discharge port in communication with the liquid flow path, for discharging the ink supplied in the liquid flow path, the ink flow path being filled with the ink for preservation containing neither colorant nor reactive component which is to be replaced by the reactive ink for recording, and
the recording head is structured with a base comprising a board which supports a heat-generating resistor forming the heat-generating section, electrode wiring electrically connected to the heat-generating resistor and cavitation-resistant film provided on the heat-generating resistor and electrode wiring via an insulating/protective layer and said ink flow path is structured to correspond to the heat-generating section, the cavitation-resistant film having a Ta or TaAl film at least in the portion which comes into contact with the ink.
The ink set suitably applicable to the method of the present invention for preserving a recording head having an ink for recording containing at least one type of reactive ink, wherein
the recording ink has at least one combination of a non-reactive ink containing a colorant in a liquid medium and reactive ink containing a reactive component reactive with another ink and colorant in a liquid medium compositionally different from that for the non-reactive ink, and is further provided with the ink for preservation of the reactive and non-reactive inks, which is the reactive ink from which the colorant and reactive component are removed.
The second embodiment of the method of the present invention for preserving a recording head for ink jet which uses the Ink for preservation includes a liquid flow path by which the ink is supplied and a discharge port in communication with the ink flow path to discharge the ink supplied into the ink flow path; is connected to an ink tank in the recording apparatus in such a way to be removably attached to or detached from the ink tank, to allow the ink to be discharged from the discharge port; and uses a recording ink having at least one combination of a non-reactive ink containing a colorant in a liquid medium and reactive ink containing a reactive component reactive with another ink and colorant in a liquid medium compositionally different from that for the non-reactive ink, comprising a step of filling the ink flow path in the recording head with the ink for preservation, composed of the reactive ink from which the colorant and reactive component are removed, to make the recording head for preservation.
The ink for preservation for the ink set is used to preserve the recording head which uses the recording ink set containing at least one combination of non-reactive ink containing colorant in the liquid medium, and reactive ink containing reactive component reacting with another ink and colorant, and is composed of the reactive ink from which the colorant and reactive component are removed.
The liquid medium for the recording ink is composed of a liquid solvent component, e.g., water, incorporated, as required, with one or more additives.
The ink for preservation in this embodiment is composed of the reactive ink from which the colorant and reactive component are removed, wherein it may be compositionally the same as or different from the reactive ink for the other components. It preferably have the common composition for the other components, viewed from efficiency of the ink production.
Preservation of the recording head filled with the ink for preservation in the method of the present invention means that of the recording head while it is kept unused during the period from completion of the examination of the as-assembled recording head for its recording conditions to its delivery, during the delivery period, and/or the period for which it is stored by the user before use. Therefore, the preserved recording head may be stationary in a storehouse or moving during the delivery.
In the method of the present invention, the ink for examination free of the reactive component is supplied into the ink flow path in the recording head, while it is examined for its recording conditions, and is replaced by the ink for preservation on completion of the examination. No troubles will occur during the preservation period, even when the ink for examination is not completely replaced by the ink for preservation.
In the method of preserving the recording head which uses the above-described ink set has two or more ink flow paths each working independently to commonize the ink for preservation to be supplied into each of the ink flow paths in the recording head structured to discharge two or more types of ink. This allows common induction replaceability of the ink for preservation in each recording head or each chip having two or more recording heads on the same board while the ink for preservation is supplied into each ink flow path, e.g., for replacing the ink for examination, improving efficiency of the replacement procedure.
Commonizing the ink for preservation for each recording head or each chip having two or more recording heads on the same board eliminates the necessity of considering matching between the ink for preservation and the recording ink set including combination of reactive inks with a component different to each other and ink containing no reactive component, thereby allowing inkset configuration with a combination providing adequate performance of each ink.